Stock-based Compensation (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Employee Stock Based Compensation Expense
Total	$ 15,104,000	$ 11,735,000	$ 10,344,000
Unvested stock options and RSUs
Employee Stock Based Compensation Expense
Unrecognized compensation expense	19,700,000
Weighted-average period of recognition of unrecognized stock-based compensation expense	25 months
Cost of product revenues | Employees
Employee Stock Based Compensation Expense
Total	441,000	335,000	342,000
Research and development | Employees
Employee Stock Based Compensation Expense
Total	3,992,000	3,017,000	2,881,000
Selling and marketing | Employees
Employee Stock Based Compensation Expense
Total	4,191,000	3,194,000	3,086,000
General and administrative | Employees
Employee Stock Based Compensation Expense
Total	$ 6,480,000	$ 5,189,000	$ 4,035,000